Bone marrow transplantation in thalassemia: modifications of hepatic iron overload and associated lesions after long-term engrafting.

Among 450 thalassemic patients treated in the Hematologic Department, 50 patients who were disease-free 4-6 years after allogeneic bone marrow transplantation were sequentially studied by liver biopsy. The patients received marrow from siblings who were genotypically HLA identical at A, B, C and DR loci. For evaluation of siderosis and associated lesions, each patient underwent liver biopsy before, and again 6 months and yearly for 4 to 6 years after bone marrow transplant. Spontaneous reversibility of liver iron overload, once the need for transfusions ceased when a functioning graft had been established, was observed in the youngest patients, aged 1-8 years, whereas iron excess remained at the end of follow-up in many patients aged 9-15 years. Hypotheses about the mechanism of the iron decrease are discussed. Several cases also obtained improvement of associated pathologies such as hepatitis, probably through modifications in the mechanisms controlling their immunological status.